Apparatus for embossing steel strip and method of treating same

ABSTRACT

STEEL STRIP IS PASSED THROUGH AN EMBOSSING APPARATUS WHICH PRODUCES A SERIES OF SPACED PROJECTIONS ALONG EACH EDGE OF THE STRIP. THE MALE EMBOSSING MEMBERS EACH COMPRISE A WHEEL HAVING A PLURALITY OF PROTUBERANCES DISPOSED ALONG THE PERIPHERY THEREOF, THE SPACING BETWEEN EACH PAIR OF ADJACENT PROTUBERANCES DIFFERING ABOUT THE PERIPHERY. THE STRIP IS THEN COILED ABOUT A VERTICAL AXIS WHEREBY SUBSTANTIALLY ALL OF SAID PROJECTIONS ABUT UNDERFORMED PORTIONS OF STRIP CONVOLUTIONS ADJACENT THERETO. HEATED GAS IS SUBSEQUENTLY PASSED BETWEEN THE CONVOLUTIONS OF THE COIL TO CHANGE THE CHARACTERISTICS OF THE METAL STRIP, AFTER WHICH THE PROJECTIONS ARE REMOVED FROM THE EDGES OF THE STRIP AND THE STRIP IS TIGHTLY COILED.

Sept. 21, 1971 YOUNG ETAL 3,506,668

APPARATUS FOR EMBOSSING STEEL STRIP AND METHOD OF TREATING SAME FiledMarch 20. 1969 2 Sheets-Sheet 1 lli-Ml W Hora/d K. Young Herbert Wa/dW/7//'am 0. Blane/7 Sept. 21, 1971 H. K. YOUNG ETAL 3,606,668

APPARATUS FOR EMBOSSING STEEL STRIP AND METHOD OF TREATING SAME FiledMarch 20, 1969 2 Sheets-Sheet 8 v ANNEALER TIGHT COILER 58 TIGHT0011.51? .60 V 6 1 WWW WASHER MASHER nous (NAT/PIC ACID) 6'2INVIiN'I'ORS Haro/dK Young Herbert Wald MMbmOB/anch United States Patent01 fice tion Filed Mar. 20, 1969, Ser. No. 808,927 Int. Cl. 323p 17/00US. Cl. 29-423 2 Claims ABSTRACT OF THE DISCLOSURE Steel strip is passedthrough an embossing apparatus which produces a series of spacedprojections along each edge of the strip. The male embossing memberseach comprise a wheel having a plurality of protuberances disposed alongthe periphery thereof, the spacing between each pair of adjacentprotuberances differing about the periphery. The strip is then coiledabout a vertical axis whereby substantially all of said projections abutundeformed portions of strip convolutions adjacent thereto. Heated gasis subsequently passed between the convolutions of the coil to changethe characteristics of the metal strip, after which the projections areremoved from the edges of the strip and the strip is tightly coiled.

BACKGROUND OF THE INVENTION This invention relates to the treatment ofmetal strip, and more particularly to an apparatus for producingprojections along the edges of a steel strip. It further relates to amethod of treating metal strip which includes the step of coiling metalstrip about a vertical axis with adjacent convolutions separated byreason of said projections.

There are many processes for treating steel strip which requires thestrip to be open Wound, i.e., Wound in such a manner that adjacentconvolutions are separated, in order to permit the entire surface of thestrip to be exposed to gases which cause a change in the characteristicsof the metal strip. Typical of these processes is the chromizingprocess, in which ferrochromium powder is compacted onto the surface ofstrip which is subsequently heated in a furnace to a temperaturesufficiently high to cause diffusion of said powder into the steel stripto provide an iron-chromium alloy coating thereon. Open coiling preventswelding of the convolutions of the coil and permits intimate contactbetween the furnace atmosphere and the surface of said coated strip.

In the past, open-Winding was generally accomplished by inserting a pairof zig-zag steel wires or the like between the convolutions of the coilduring winding thereof, each wire being spaced about one inch from thetop and the bottom edge of the strip, respectively. These wires wereremoved from the strip while unwinding the coil following the chromizingheat treatment. However, the wires frequently became brittle and, inaddition, stuck to the surface of the strip as a result of said heattreatment. Consequently, said wires broke during the unwindingoperation. In addition, at least two men were required for the removalof said wire.

It has been suggested that the convolutions of a coil of strip can beseparated by providing indentations, and corresponding projections,along the edges of the strip. However, this method of separationappeared impractical, since the projections along the edges of oneconvolution would frequently nest in the indentations along the edges ofan adjacent convolution.

It" is an object of this invention to provide an apparatus for embossingthe edges of steel strip whereby said strip can be open wound withoutthe occurrence of nesting.

It is a further object to provide a method of treating steel strip whichutilizes such an apparatus.

3,606,668 Patented Sept. 21, 1971 SUMMARY OF THE INVENTION We havediscovered that the foregoing objects can be attained by providing anapparatus comprising a shaft, rotatably mounted in a frame, having firstand second Wheel members coaxially secured thereto. Disposed along theperiphery of each Wheel member is a plurality of spaced protuberances,at least some of the spaces between adjacent protuberances beingunequal. Also rotatably mounted in said frame is a back-up roll having aplurality of grooves in the peripheral surface thereof, said groovesbeing adapted to mate with said protuberances during rotation of saidshaft.

Steel strip which has been passed through the apparatus of the inventionis characterized by a plurality of spaced projections along each edgethereof. The strip can be coiled about a vertical axis wherebysubstantially all of said projections abut undeformed portions of stripconvolutions adjacent thereto, and the coiled strip then can besubjected to treatment to change the characteristics of the metal strip.In the narrower aspects of the method of the invention, the projectionscan subsequently be removed from the edges of said strip.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmented front elevationshowing salient features of the apparatus of the invention.

FIG. 2 is an enlarged sectional view, taken along the lines 22 of FIG.1, partially cut away to show details of the subject apparatus.

FIG. 3 is a schematic diagram of the apparatus utilized in a chromizingheat treatment operation.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIG. 1, the subjectapparatus comprises a framework 10 comprising a pair of verticalchannels 12 the upper ends of which are connected by a horizontalchannel 14. Said framework is provided with a conventional supportingbase (not shown), and further com prises a horizontal bearing plate 16connected between the vertical channels 12. Secured to the channel 14and the bearing plate 16 are fixed bearings 18 which house the shaft 20of a vertically disposed female embossing roll 22. Disposed adjacent tosaid fixed bearings, and also secured to said channel 14 and bearingplate 16, are horizontally adjustable bearings 24 which house the shaft26 of a vertically disposed male embossing member 28. Each of saidadjustable bearings 24 is provided with a collar (not shown) whichthreadedly engages a screw 30 connected to a hand wheel 32 the rotationof which moves said bearing horizontally. Thus, the gap between thefemale roll 22 and the male member 28 can be adjusted to accommodatestrip of various gauges. The shafts 20 and 26 are provided with meshinggears 34 whereby said shafts can be rotated synchronously.

The male embossing member 28 comprises a pair of vertically adjustablehubs 36 which are keyed to the shaft 26. One of said hubs is secured tothe lower end of the shaft 26, while the other hub is adapted to besecured to any point along the upper half of said shaft, the exact pointbeing dependent upon the width of the strip to be embossed. Secured toeach of the hubs 36 is an embossing wheel 38 having a plurality ofspaced protuberances 40 disposed along the periphery thereof. In orderto substantially decrease the probability of projections along the edgesof a strip nesting in corresponding indentations in adjacentconvolutions during coiling of said strip, at least some of the spacesbetween adjacent protuberances are unequal. Preferably, as is shown inFIG. 2, the spacing differs between every pair of adjacentprotuberances. In order to prevent the simultaneous alignment of aprojection and an indentation at both the 3 upper and the lower edges ofthe strip, the upper and lower wheels 38 have their protuberances 40axially misaligned.

Each of the protuberances 40 comprises a square having one end machinedto a blunt point to provide a projection. Each square is inserted into asleeve 42 which is press fitted into an axial bore in the wheel 38. Theinner end of the sleeve 42 is threaded and is provided with a screw 44whereby the axial position of the square, and hence the extent to whichthe protuberance 40 projects beyond the periphery of the wheel 38, canbe adjusted. The square is secured in position by means of a set screw46.

The female embossing roll 22 is provided with a plurality of grooves 48in the peripheral surface thereof. Said grooves are adapted to mate withthe protuberances 40, and preferably are axially disposed as shown inthe drawings. Said grooves may, however, be circumferentially disposed,each groove being adapted for use with strip of a particular width, inwhich case there is no need for synchronization of the rotaiton of themale and female members. FIG. 2 shows the projections 49 in a strip 50passing between a male embossing wheel 38 and a female roll 22 havingaxial grooves therein.

FIG. 3 shows a typical utilization of the apparatus of the invention,viz, as part of the apparatus used in a chromizing heat treatment. Asdetails of the chromizing process may be found in US. Pat. No. 3,312,546to E.H. Mayer et al., issued Apr. 4, 1967, and assigned to the assigneeof the subject invention, the process will be described herein onlybroadly.

Steel strip 50 having a coating of ferrochromium powder impacted thereonis placed on the tight coil table 52 of a conventional open windingmachine, The strip 50 is pulled through the embossing machine 54 of theinvention and open wound on the loose coil table 56 of said open windingmachine whereby substantially all the projections 49 along the edges ofthe strip 50 abut undeformed portions of strip convolutions adjacentthereto. The open coil is then placed in an annealing furnace 58 andheated in a controlled atmosphere, preferably including a halogen gas,to cause diffusion of chromium into the surface of the steel strip 50.

After the heat treatment in said annealing furnace 58, the strip 50 isplaced on the open coil table 60 of a second conventional open windingmachine, and is passed through a set of masher rolls 62 which remove theprojections 49 from the edges of the strip 50. Alternatively, the stripmay be passed through a conventional edge-trimming machine. The strip isthen washed in a bath 64 of dilute nitric acid to remove therefromtraces of any halides that may have deposited thereon, and tight woundon the tight coil table 66 of said second open winding machine.

Subsequently, the strip may be processed in the usual manner, e.g.,skin-rolled, slit and sheared.

We claim:

1. A method of treating metal strip, comprising:

(a) producing a series of spaced projections in said strip only alongeach side edge thereof, at least some of the spaces between adjacentprojections being unequal, the projections along one edge of said stripbeing longitudinally misaligned relative to the projections along theother edge thereof,

(b) coiling said strip about a vertical axis whereby substantially allof said projections abut undeformed portions of strip convolutionsadjacent thereto, thereby separating adjacent convolutions by a distanceequal to the height of said projections,

(c) treating the coiled strip, while the coil axis is maintainedvertical to change the characteristics of the metal strip, and

(d) passing said strip through rolls which flatten said projections.

2. An apparatus for producing a series of projections in a strip onlyalong the side edges thereof, comprising:

(a) a shaft rotatably mounted in a frame,

(b) first and second wheel members coaxially secured to said shaft,

(c) a plurality of spaced protuberances disposed along the periphery ofeach of said wheel members, at least some of the spaces between adjacentprotuberances being unequal, the protuberances on said first wheelmember being axially misaligned with respect to the protuberances onsaid second wheel member,

((1) a back-up roll rotatably mounted in said frame adjacent to saidwheel members, and

(e) a plurality of grooves in the peripheral surface of said back-uproll, said grooves being adapted to mate with said protuberances duringrotation of said shaft.

References Cited UNITED STATES PATENTS 2,083,518 6/1937 Lorig 72379X2,089,892 8/1937 Greulich 72196 2,257,760 10/1941 Myberg 72196X2,991,550 7/1961 Block 11748X 3,027,628 4/1962 Wilk et al. 29-6053,222,212 12/1965 Samuel et al. 117107.2 3,290,184 12/1966 Minck 148163,453,726 7/1969' Roen 29-609X JOHN @F. CAMPBELL, Primary Examiner V. A.DI PALMA, Assistant Examiner US. Cl. X.R.

